For SK Telecom, Korea's biggest network carrier with 50.3 percent market share, preorder units sold out in 9 hours, while it took just three days for KT and LG Uplus to sell all of their preorder supply. All three carriers had set a limited preorder time span, from September 18 to September 25.

Samsung has also expedited the official launch dates of the Galaxy Note 4, deciding to hold a press conference on September 24 and launch on September 26. Many industry analysts have speculated that Samsung is hurrying for early entry in response to Apple's iPhone 6 and Watch, which garnered significant attention when it was unveiled earlier this month.

The Samsung Galaxy Note 4 is the company's latest phablet. Announced earlier this month at the IFA tradeshow in Berlin, the Note 4 brings about a new metal frame design while still packing in a stylus. It comes with a 5.7-inch Quad HD display with a super-sharp resolution of 2,560x1,440-pixels and a 16-megapixel rear camera. The Korean version of the Note 4 packs an Exynos 5433 octa-core processor, unlike the global version, which comes with a quad-core Snapdragon 805.

The Galaxy Note 4 has been marked with a list price of 957,000 Korean Won or $920. This price point is actually the lowest ever for any of the Galaxy Note iterations. Last year's Galaxy Note 3 cost 1,067,000 million won or $1,025 at the time of launch.

Korea's smartphone distribution market will likely see a substantial jump in sales with the launch of the Galaxy Note 4 and iPhone 6, a sigh of relief for Korean network carriers and retailers. Phone sales had been dropping consistently for the past year, in large part because of changes in handset subsidy regulations enforced by the government.